94. 二叉树的中序遍历

python

class Solution:
    def inorderTraversal(self, root: TreeNode) -> List[int]:
        if not root:
            return []
        return self.inorderTraversal(root.left) + [root.val] + self.inorderTraversal(root.right)

c++

class Solution {
public:
    void inorder(TreeNode* root, vector& res) {
        if (!root) {
            return;
        }
        inorder(root->left, res);
        res.push_back(root->val);
        inorder(root->right, res);
    }
    vector inorderTraversal(TreeNode* root) {
        vector res;
        inorder(root, res);
        return res;
    }
};